Image display

Abstract

A method for displaying an image to a pilot ( 20 ) of an aircraft ( 2 ). The method comprises: displaying, by a helmet mounted display (HMD) ( 24 ), to the pilot ( 20 ), an image comprising initial image components including a first image component ( 34 ); determining that the helmet mounted display ( 24 ) is offset from a desired position for the helmet mounted display ( 24 ); determining, by one or more processors ( 26 ), a specification for a further image component ( 50 ); and displaying, by the helmet mounted display ( 24 ), to the pilot ( 20 ), an image comprising at least the first image component ( 34 ) and the further image component ( 50 ). The further image component ( 50 ) has a fixed position with respect to the first image component ( 34 ) and indicates one or more alternative positions for the first image component ( 34 ).

1 . A method for displaying an image to a pilot of an aircraft, the method comprising:
 displaying, by a helmet mounted display, to the pilot of the aircraft, an image comprising one or more initial image components, the one or more initial image components including a first image component;   providing, to one or more processors, an indication that the helmet mounted display is offset from a desired position for the helmet mounted display, the desired position of the helmet mounted display being a position in which, when the pilot controls the aircraft to perform a predefined operation, from the pilot's point of view, an initial image component displayed on the helmet mounted display is at a predefined position relative to one or more objects or features that are remote from the aircraft;   determining, by the one or more processors, a specification for a further image component; and   responsive to the one or more processors receiving the indication, displaying, by the helmet mounted display, to the pilot of the aircraft, an image comprising at least the first image component and the further image component; wherein   the further image component has a fixed position on the helmet mounted display with respect to the first image component and indicates, to the pilot, one or more alternative positions on the helmet mounted display for the first image component.   
     
     
         2 . A method according to  claim 1 , wherein the step of determining the specification for the further image component comprises:
 providing a value for a distance by which the helmet mounted display is offset from the desired position for the helmet mounted display; and   using the provided distance value, determining the specification for the further image component.   
     
     
         3 . A method according to  claim 1 , wherein the further image component further indicates, to the pilot, the relative probabilities of the one or more alternative positions for the first image component being the same as the position that the first image component would have if, were the pilot to control the aircraft to perform the predefined operation, from the pilot's point of view, an initial image component was at the predefined position relative to the one or more objects or features that are remote from the aircraft. 
     
     
         4 . A method according to  claim 3 , wherein
 the further image component indicates, to the pilot, a plurality of alternative positions on the helmet mounted display for the first image component with respect to the objects or features that are remote from the aircraft; and   the step of determining the specification for the further image component comprises:
 for each of the alternative positions for the first image component, providing a value for a probability that that position for the first image component is the same as the position that the first image component would have if, were the pilot to control the aircraft to perform the predefined operation, from the pilot's point of view, an initial image component was at the predefined position relative to the one or more objects or features that are remote from the aircraft; and 
 using the provided probability values, determining the specification for the further image component. 
   
     
     
         5 . A method according to  claim 1 , wherein
 the further image component is a V-shaped symbol;   the length of the V-shaped symbol indicates a range of alternative positions for the first image component with respect to the objects or features that are remote from the aircraft, the length of the V-shaped symbol being a distance between the tip of the V-shaped symbol and the ends of the arms of the V-shaped symbol; and   the distance between the arms of the V-shaped symbol at a point along the length of the V-shaped symbol indicates a relative probability that the alternative position for the first image component corresponding to that point along the length of the V-shaped symbol is the same as the position that the first image component would have if, were the pilot to control the aircraft to perform the predefined operation, from the pilot's point of view, an initial image component was at the predefined position relative to the one or more objects or features that are remote from the aircraft.   A method according to  claim 1 , wherein the first image component is a Ship Reference Velocity Vector scale for aiding the pilot to land the aircraft.   
     
     
         7 . A method according to  claim 1 , wherein:
 the first image component is a linear object that extends horizontally across at least part of the display; and   the further image component indicates one or more alternative vertical positions on the helmet mounted display for the first image component.   
     
     
         8 . A method according to  claim 1 ,
 wherein the step of providing the indication to the processor comprises:   controlling, by the pilot, the aircraft to operate in a straight and level state;   determining that, during the straight and level state, one or more of the initial image components do not, from the pilot's point of view, coincide with a corresponding object or feature remote from the aircraft; and   responsive to the determination that, from the pilot's point of view, one or more initial image components do not coincide with a corresponding object or feature remote from the aircraft, providing, to the processor, the indication.   
     
     
         9 . A method according to  claim 8 , wherein the step of determining that, during the straight and level state, one or more initial image components do not, from the pilot's point of view, coincide with a corresponding object or feature remote from the aircraft comprises determining, by the pilot, that, during the straight and level state, one or more horizon bars displayed on the helmet mounted display do not, from the pilot's point of view, coincide with the horizon as seen by the pilot through the helmet mounted display. 
     
     
         10 . A method according to  claim 1 , wherein the processor is wholly located onboard the aircraft. 
     
     
         11 . A method according to  claim 1 , the method further comprising controlling, by the pilot, the aircraft dependent upon the displayed further image component. 
     
     
         12 . Apparatus for displaying an image to a pilot of an aircraft, the apparatus comprising:
 a helmet mounted display configured to display, to the pilot of the aircraft, an image comprising one or more initial image components including a first image component; and   one or more processors configured to:
 receive an indication that the helmet mounted display is offset from a desired position for the helmet mounted display, the desired position of the helmet mounted display being a position in which, when the pilot controls the aircraft to perform a predefined operation, from the pilot's point of view, an initial image component displayed on the helmet mounted display is at a predefined position relative to one or more objects or features that are remote from the aircraft; and 
 determine a specification for a further image component; wherein 
   the helmet mounted display is further configured to, responsive to the indication being received by the one or more processors, to the pilot of the aircraft, display an image comprising the first image component and the further image component; and   the further image component has a fixed position on the helmet mounted display with respect to the first image component and indicates, to the pilot one or more alternative positions on the helmet mounted display for the first image component.   
     
     
         13 . An aircraft comprising apparatus according to  claim 12 . 
     
     
         14 . A program or plurality of programs arranged such that when executed by a computer system or one or more processors it/they cause the computer system or the one or more processors to operate in accordance with the method of  claim 1 . 
     
     
         15 . A machine readable storage medium storing said program or at least one of the plurality of programs according to  claim 14 .